Machine and method for forming and bending tubes



F. KRITZ.

MACHINE AND METHOD FOR FORMING AND SENDING TUBES.

I APPLICATION FILED DEC-11,1920.

Patented June 20, 1922.

4 SHEETS SHEET I.

F. KRITZ.

MACHINE AND METHOD FOR FORMING AND SENDING TUBES. APPLICATION FILED DEC.II. 1920.

1 AQQQQQ. Patented June 20, 1922.

4 SHEETSSHEET 2- "fig? INVENTOR.

A TTORNEY.

F. KRITZ.

I MACHINE AND METHOD FOR FORMING AND BENDING TUBES.

APPLICATION FILED DEC. 11, 1920.

j], AQQQOQZ Patented June 20, 1922 4 SHEETS-SHEET 3.

..LN V EN TOR.

A TTORNE Y.

F. KRITZ.

MACHINE AND METHOD FOR FORMING AND BENDING TUBES.

. APPLICATION FILED 012cm, 1920. LQQQQQL-QQ Patented June 20, 1922.

4 SHEETS-SHEET 4.

I N V EN TOR.

A TTORNEY.

tartan stares PATENT @FFHCE.

FRANK KRITZ, OF DETROIT, MICHIGAN.

Specification of Letters Patent.

Patented June -20, 1922.

Application filed December 11, 1920. Serial No. 429,914.

T all whom it'may concern: I Be it known that I, FRANIcKRrr a citizen ofthe United States, residmg at Detrolt,

- in the county of Wayne and State of Michigan have invented certainnew. and useful Improvements in Machines and Methods for Forming andBending Tubes. of which the following is a specification.

This invention relates to tube forming and bending machines. It is theobject of this inventionto provide a machine which will both form apiece of flat ribbon stock into a tube or moulding and simultaneouslybend the same. One of the main objects of the machine is to form tubingthat may be used to construct the rims of steering wheels. but obviouslythe invention is capable of a wider application. The machine is capableof making a coil of tubing or moulding from a flat ribbon of metal or itcan be used to make short lengths of tubing or moulding intosubstantially circular form. lVbere a long coil of tubing or moulding ismade the operation is substantially automatic. the strip of flat stockbeing run through the various bending and shaping devices and emergingat the final end as a completely formed coil of tubing or moulding. Thecoil may then be cut up into short lengths permitting the forming ofcircular rims.

Where relatively short lengths of tube or moulding are formed and bentthe operation is substantially. the same but the action is notautomatic. The product has to be taken from one device to the other byhand. This will more fully appear when the specific construction isunderstood.

In the drawings,

Fig. 1 is a front elevation of the machine showing, however, only theparts above the bed and with the guiding blocks and supporting partstherefor removed.

Fig. 2 is an end elevation of the machine.

Fig. 3 is a fragmentary plan view of the machine.

Fig. 4 is a fragmentary front elevation showing the stock passingthrough the rolls. This is taken at the extreme right of Fig. 1.

Fig. 5 isa perspective of the guide block.

Figs. 1. 1". 1. 1 and 1 are sections of the work taken after it haspassed through rolls 11, 22, 33. 4-4. and 5+5. respectively.

This machine is capable of use to make either tubing or moulding. I haveillustrated a machine that is adapted to making tubing and consequentlythroughout the specification specific reference may be made to tubingbut I wish it understood that the machine has a broader application thansimple tubing and is not restricted to this alone.

(1 represents the bed of the machine which is supported upon a sub-bed bby means of the large I-beams c. This sub-bed b is supported upon legs(i. (I. Upon the bed a are supported a plurality of standards 0 whichjournal the single lower shaft 7' and the several upper shafts 9. Thesestandards are bolted to the bed a. It is necessary to make the uppershaft separate because otherwise some of the upper rolls. because oflarger diameter. would run faster at the middle of their peripheriesthan their companion lower rolls. This would not be permissible inpulling on a single continuous piece of stock that runs through all therolls. 'lhese upper shafts 1 are driven by a train of gears it from thelower shaft 7' and consequently can have the proper gear ratio to giveeach upper roll its proper speed. A large gear 1? on the end of the longlower shaft f is driven by a driving pinion which very materiallyreduces the speed.

The rolls 1. 1 are secured on the upper and lower shafts byu-ollars issecured thereto by set screws. The stock is drawn off from a roll 7 offlat ribbon steel or of other suitable material. This runs down througha chute In between the staggered pins 11 and over the maple block 0which is detailed in perspective in Fig. 5. This block 0 is formed togradually taper toward the cross-sectional shape of the rods and is heldin a saddle p. which is a casting and which is guided to slide in thedove-tailed guide q. The hand screw 1' has one end secured rotatably inthe saddle and is threaded through the upstanding lug s in the end ofthe dove-tailed guide 9. lt'will be seen that these dovetailed guidesare simply castings with cap plates t bolted thereto. the castings beingbolted to the bed of the machine by bolts u. By turning the hand wheelthe saddle 1) may be advanced toward or away from the set of rolls 1. 1.thereby varying the diameter of the bend given the stock. as willpresently be described.

The first set of rolls 1. 1 is calculated to give the stock a shaping oeration and in connection with the maple vlock 0 to also give it alongitudinal bending. The first i take successively smaller coils.

racks.

cross-sectional shaping is that shown bythe cross-sectional view Fig. 1below the rolls 1, 1 in Fig. 1. It will there be apparent that the firstshaping operation is to slightly concave the center of the cross sectionand slightly turn in the edges of the strip. At the same time the stripis bent into the circle or coil as shown at r (Fig. 2). This isaccomplished because the guiding surface of the block 0 is-angularlyoffset with respect to y the perpendicular to a line through the axes ofthe'upper and lower rolls. In ordinary metal forming operations thestock is guided to the two rolls on a line substantially perpendicularto the line through the axes of the upper and lower rolls. vConsequentlythereis little or no tendency of the metal to bend. It is my purpose toguide the stock to the rolls so as to produce a pronounced but gradualbending at the-same time, the cross-sectional shaping occurs. For thispurpose, as already explained, I utilize the maple blocks which aresuperior to rolls for this purpose as the apex of the block can bebrought up very closely to the point where the two rolls pinch thestock.

On the opposite side of the two rolls is located a slide a: whichjournals an idler roller bend still sharper and assume a coil of lessdiameter. It will be noted that in the second set of rolls no chutem isused or needed. When the stock comes out of the second set of rollsithas the cross-sectional shape shown in Fig. 1". It will be seen thatthe lower roll of this set is concaved and the upper roll is sharplyconvex with two flanges at either end arranged to turn in the edges of.thestock, as shown in Fig. 1.

The same operation obtains in the third set of rolls designated 3, 3.The lower roll is concaved, the upper roll is even more convex than theupper roll of set #2, and the flanges form deep recesses between theflanges and the convex portion of the roll in which the edges of thework are turned over more, as will be apparent from the cross-sectionalshowing in Fig. 1. At the same time the main portion of the strip isbeing bent up more into V shape. In connection with this set of rolls isalso utilized a guiding, block which serves to reduce the diameter ofthe coil, as will be evident from the position of the rack 16 onto whichthe coil is fed. The same operation occurs in connection with the rolls4, 4 except that here the central convex portion is narrower than in theprevious 3 This is carried in a dove-tailed guide-: in the same way thatthe saddle on the opposite side is, and the hand w 1861 10 and screw 11permits thev adjustment of this slide back and forth. This roll is notintended to constrain the metal to bend but simplyas a supporting andguide roll for the strip asit comes in its bent from out of the rollsand block.

Above each set of rolls is located a rack supported on suitable posts13. These racks are designated 14, 15, 16 and 17. Note that they are ofsuccessively less distance from the rolls and consequently are arrangedto Fi.ch rack is. provided with upstanding pins 18 which keep the coilsproperly arranged on the As already explained, the stock passes alongthe chute m between thestaggered pins 91 into the first set of rolls andemerges therefrom having a cross-sectional form such as shown in Fig.1*. At the same time, due to the angular ofi'setting of the guide block0, the stock is caused to take the coil'form shown at e in Fig. 2.Similarly the second set of rolls and the flanges at the ends of theupper roll form deeper recesses at the sides of the central convexportion of the roll to further turn in the bead or the edges of thestrip, and the main portion of the strip is formed into a morepronounced U shape, as shown in Fig. 1 inthe cross-sectional showing.

The fifth set of rolls 5, 5 are the final or closing rolls. The lowerroll is a plain concaved roll and the upper roll is a plain concavedroll except for a slightly raised guiding fin 20. This roll serves topress the edge portions of the strip together and also press the edgesdown to form the complete bead, resulting in the tubular cross-sectionalshape as shown in Fig. 1 This forms a very nice shape for the rim of asteering wheel of an automobile. The beading turns in the raw edges ofthe metal so it is perfectly smooth and the cross-sectional shape issuitable for comfortable operation of the wheel. However, obviouslyvarying cross-sectional shapes can be made without departing from theinvention.

The metal leaves the final set of rolls and runs onto a rack. 21, whichis provided with spools 22 to keep properlyspaced the variousconvolutions of the coil.

The secret of the success of this form of operation is to gradually butcoincidently shape the strip both longitudinally and cross-sectionally.If it were attempted to give the strip either its finalcross-sectionalshape or its final longitudinal bending in one operation. it would sodraw the metal that the same would wrinkle and the operacoil may bevaried, but if a coil of co siderable variation from what the machinewas built to manufacture is to be made, it is preferable to use adifferent set of blocks.

The operations heretofore defined with respect to a continuous strip ofmetal can be performed on short lengths of stock of substantially thelength of the circumference of the intended rim. In such a case,however, each operation has to bee separate one and the coil is passedfrom one set of rolls to the other by hand. Obviously when the machineis so operated it is notnecessary that the rolls all be in line.

It will be obvious that rolls might be used in place of wooden blocks asthe guiding surface is angularly removed from the perpendicular to thecenter line through the two rolls. However, a roll is not nearly as goodfor this purpose.

In some of the claims reference is 'made to the lower shaping rolls allbeing in line. ()bviously, by re-arrangement, it is possible to put allthe upper rolls in line and the lower rolls in non-alignment. Hence thisreference must be taken to be words of description and notof limitation.

Nhat I claim is: 1

Lin a machine for forming and shaping metal tube or moulding. thecombination of a plurality of sets of section-shaping rolls, and meansoperating in conjunction with each set and coincidently therewith forbending the said tube or moulding longitudinally into coils ofprogressively smaller diameter after each pass.

2. In a machine for forming and bending a tube or moulding, thecombination of a plurality of sets of section-shapmg rolls, and aplurality of members having guiding surfaces co-operating one with eachset of saidshaping rolls and each guiding member placed at a greaterangle to the perpendicular to the line normal to the axes of the shapingrolls for the purpose of causing the longitudinal curvature. of saidtubing or moulding and reduction of the radius of such curvature.

3. lln a machine for forming and bending tubing or moulding. thecombination of a plurality of sets of shaping rolls. and a plurality ofguiding members one with each set of shaping rolls having guidingsurfaces progressively further angularly removed from the perpendicularthrough the line normal to the axes of the rolls for giving the tubing agradually increasing longitudinal curvature coincidently with itspassing throu h the shaping rolls.

4. n a machine for forming and bending metal tubing or moulding. thecombination of a plurality of sets of shapingrolls, and a plurality ofguiding members one with each set of shaping rolls provided with guidingsurfaces offset at progressively greater angles withrespect to theperpendicular to .the line normal to the axes of the rolls from thefirst set of rolls to the final set of rolls for gradually curving anddiminishing the radius of the curvature of the tubing or moulding as thesame is coincidently shaped into the proper cross section.

, 5. In a machine for forming and bending metal tubing or moulding, thecombination of a plurality of pairs of shaping rolls, a guidin member inproximity with each pair of shaping rolls having a guiding surfaceangularly removed from the perpendicular to the line normal to the axesof the pairs of rolls, each guiding surfacebeing ofiset at a greaterangle with respect to such perpendicular from the first set of rolls tothe final set of rolls to reduce the radius of the coil. Y

6. In a machine for bending and forming metal tubing, the combination ofa plurality of pairs of shaping rolls having surfaces arranged to take aflat piece of ribbon and. gradually curve the cross section of the sameand turn in the edges and press the whole together to form asubstantially closed tube having meeting edges, the said rollscomprising an initial pair of rolls, one having a concaved crosssectional surface and the other a convex complementary cross sectionalsurface, a final pair of rolls having concaved surfaces arranged topress the tube parts and headed edges together, and intermediate pairsof rolls having center portions that are convex on one roll andcomplementarily concave on the other roll with grooves at either sidearranged to gradually turn in the head.

7. In a machine for bending and forming metal tubing, the combination ofaplurality of pairs of shaping rolls having surfaces arranged to take afiat piece of ribbon and gradually curve the cross section of the sameand turn in the edges and press the whole together to form asubstantially closed tube having turned-in or beaded meeting edges,

the initial pair of rolls comprising a convex sively turn the edges into form the bead.

8. In a machine for forming and bending metal tubing or moulding,comprising a plurality of pairs of rolls all arranged with the lowerrolls in alignment and shaped to pro gressively shape the cross sectionof the tubing or moulding, and means located in proximity with the rollsfor causing the tubing or moulding when leaving the shaping rolls tobend into a coil, said parts being arranged so that the work is fedcontinuously through all the sets of rolls in the form of coils fromroll to roll.

9. A machine for forming and bending metal tubing or moulding, having incombination, a plurality of sets of shaping rolls having the lower rollsin alignment, and guiding members in proximity'with the rolls andarranged in conjunction with the rolls to coincidently cause the tubeleaving the rolls to bend in coils of progressively less diameter, saidwork being fed through the shaping rolls and the guides continuously inthe form of coils from one set of rolls to the next.

10. .A machine for forming and bending metal tubing or moulding, havingin combination, a plurality of sets of shaping rolls arranged with thelower rolls in alignment, and guiding members located in proximity witheach set of rolls and angularly removedfrom the perpendicular to theline normal to the axes of the rolls, the degree of angular offsetincreasing from the first set of rolls to the last set of rolls wherebythe WOI'k can be fed through the rolls continuously in the form of coilsof decreasing diameter.

11. The method of shaping and bending metal tubing or moulding, whichcom rises the moving of a strip of metal longitudinally and coincidentlysubjecting the same to stresses calculated to fashion its cross sec tionand stresses calculated to fashion its longitudinal run into a coil ofprogressively reduced diameter as the strip meets successive stresses.

12. The method of forming and bending metal tubing or moulding, whichcomprises the moving of a metal strip longitudinally and while so movingsubjecting the same to the restraint of successive sets of obstaclescalculated each set to progressively shape the cross section of themetal and coincidently cause the tubing or moulding to coil lengthwisein a progressively reduced diameter after going through eachset.

13. The method of forming and bending the'said strip being ed throngmetal tubing or moulding, which comprises causing a metal strip totravel longitudinally and subjecting the same successively toindependent sets of stresses, each set calculated to coincidently bothprogressively shape its cross section and bend it longitudinally on aprogressively Smaller radius, the successive sets calculated to bringthe shapes gradually nearer the final shape.

14. In a machine for forming and shaping metal tubing and molding, thecombination of a plurality of sets of rolls, and means operating inconjunction with each set'of rolls for bending the said Striplongitudinally into coils of progressively smaller diameter after eachpass.

15. In a machine for forming and shap ing metal tubing or molding, thecombination of a plurality of sets of rolls. and separate guide meanslocated in proximity with each set of rolls and acting coinci dentallywith said rolls for bending the said tubing or molding longitudinallyinto coils of progressively smaller diameter after each pass.

16. In a machine for forming or shaping metal tubing or molding, thecombination of a plurality of sets of rolls, and separate guiding meansoperating in connection with each set of rolls and coincidentallytherewith for bending said tubing or molding longitudinally, eachsucceeding guiding means having a larger angle to the per-- pendicularto the center line of the roll set for progressively reducing thediameter of the coil after each pass.

17. In a machine for forming and shaping metal tubin or molding, thecombination of a plurality of sets of shaping rolls, the said roll setsbeing arranged in end to end relation, and means for guiding and coilinga strip of metal to feed the same continuously through said end to endarranged rolls in the form of a plurality of coils.

18. In a machine for forming and shaping metal tubing or molding, thecombination of a plurality of sets of section shaping rolls arranged inend to end relation and guiding means operating in conjunction with theplurality of said sets of rolls'for feeding a metal strip continuouslythrough said end to end arran ed shapinf rolls and the rolls in the formof a plurality of coils of gradually reducing diameter.

n testimony whereof I affix my signature.

FRANK KRITZ.

